1. Field of the Invention
This application relates to securing a light source to a housing opening without using cement. More particularly, the application is directed to a clip for mounting or securing a ceramic metal halide light source to the neck of a reflector, although it will be appreciated that it will also find use with any light source having a glass or quartz seal where the mounting clip can engage the seal area and secure the light source to the reflector body.
2. Discussion of the Art
Existing lamp designs typically cement a light source inside a reflector. For example, in a halogen reflector lamp, the light source is a filament tube and it is desirable for the filament tube to be located near a focal point of the reflector. This is achieved by aligning and cementing relatively stiff leads of the filament tube to the reflector. The leads are made, for example, of a nickel-iron alloy and extend through the neck of the reflector where they are subsequently fixed in place with a high-temperature cement. Although the cement is effective in holding the light source in place, it is desirable to eliminate the curing process associated with the cement, or eliminate use of the cement in its entirety because of the increased time associated to manufacture lamps according to this arrangement. More recent designs use a glass support member, or what is often referred to as a button, which has a pair of small diameter openings that receive the leads therethrough. The button provides a wall or a bottom to the neck cavity to hold the cement in place as it is cured.
Generally, the same mounting arrangement used with halogen reflector lamps has been employed with regard to securing ceramic arc tubes in an associated reflector neck. As will be appreciated, the light source for a ceramic metal halide includes a pair of arc leads spaced apart in a ceramic arc tube. The arc tube is enclosed in a quartz capsule to provide a hermetically sealed environment. A pair of molybdenum foils are sealed in a pinch region of the quartz capsule and molybdenum leads extend outwardly from the foils in the pinch region for electrical connection with an external source. The external molybdenum leads are not as stiff as nickel-iron leads. Due to the difference in stiffness, the ceramic metal halide reflector lamps encounter increased damage during shipment or transit since the molybdenum leads are less stiff and the ceramic metal halide capsule is significantly heavier than the equivalent halogen filament tube.
As noted above, presently available commercial embodiments of the ceramic metal halide lamps support the capsule by cementing it directly to the neck of the reflector. This requires that the quartz capsule pinch region be dimensioned sufficiently small to fit through the opening in the end of the reflector neck. The assignee of the present application employs a glass button for receipt through the neck opening to support the ceramic metal halide capsule where the button is held in place with cement. Commonly assigned, co-pending U.S. application Ser. No. 09/075,609, filed May 11, 1998, now U.S. Pat. No. 6,163,102, is directed to a preferred mounting arrangement having improved shock and vibration characteristics.
Nevertheless, the elimination of cement is still a desirable goal because of the difficulty encountered in handling the lamp components, controlling the introduction of the cement, and the extended time required to cure the cement. Thus, although the noted arrangement in the commonly assigned application demonstrates improvements in mounting a ceramic metal halide capsule to a reflector body, further improvements are desired.
U.S. Pat. No. 5,744,901 discloses a reflector lamp for a ceramic metal halide capsule that uses an annular sleeve to grip an external portion of the neck and light source. However, the circumferential wall of the mounting member is secured to the reflector body with a relief so that even if directed to a cement-free arrangement, the complex shape of the mounting member appears expensive to tool. Furthermore, the assembly would require expensive changes in all of the associated lamp components; namely, the capsule, base, and reflector.
Thus, a need exists to provide a simple, cement-free arrangement for securing a ceramic metal halide capsule to a reflector body with minimal modification to the lamp components.
A new and improved lamp assembly is provided that secures a light source to a reflector body in a simple, effective manner.
In an exemplary embodiment of the invention, the lamp assembly includes a body having a cavity and a reflector surface. A light source is received in the body cavity and a mounting clip engages the light source within the body cavity for precisely and rigidly locating the light source therein.
The mounting clip preferably grips the light source along axially spaced regions, in the preferred arrangement gripping a pinch seal region of the light source.
The mounting clip preferably includes a pair of legs that are spread apart to grip the pinch seal region of the light source and a portion that engages an internal surface of the neck, preventing inadvertent removal of the mounting clip from the body.
In another exemplary embodiment, an insulator is received around each lead extending from the light source for electrically isolating the lead from the clip.
A principal advantage of the invention resides in the secure mounting arrangement that eliminates use of cement for securing a light source to the reflector body.
Another advantage of the invention resides in the limited modifications required to existing lamp components.
Still another advantage of the invention is provided by the elimination of a component, and its attendant cost.
Yet another advantage of the invention is associated with the ease of manufacture of the mounting clip and decreased time required to assemble the lamp.